92 Algae. 



b}' Mr. J. Stanley Gardiner in a hitherto almost unknown region 

 of the Western Indian Ocean. The interesting notes of the col- 

 lector are published under the readings of the various localities, 

 together with remarks by M. Foslie on the occurrence ofthe different 

 species in various places. The localities include the Chagos Archi- 

 pelago, Cargados Carajos, Saya de Malha Banks, Coetiv}", 

 Providence, Amarante, and the Seychelles Archipelago. 



A coniparison between the area in question and otherparts ofthe 

 Indian Ocean shows a close correspondence with the Maldive 

 Islands, the onlj^ part which has been well worked already and 

 that was done by the same collector Mr. J. Stanly Gardiner in 

 1899—1900. This correspondence chiefly concerns the three reef- 

 building species, Lithophyllum oiikodes, L. craspediuni and Goiiioli- 

 thon friitescens, the fourth reef-building species, L. Gardineri, having 

 hitherto only been found in the Chagos and at Coetivy. These 

 species are important reef-builders in the littoral region and the 

 uppermost part of the sublittoral region of rather large areas of 

 the Indian Ocean. Lühophylliiin Kaiseri {pallescens) and other 

 species here and there contribute to the formation of reefs, but 

 apparently to a far less degree. In places where Lithothauinia occur 

 in great abundance, practically forming entire atolls, the number of 

 species is small, and each appears in an enormous number of indi- 

 viduals. This fact has been observed at the Ellice and Gilbert 

 Islands, as well as in the Indian Ocean. On the other band, in 

 places where LithotJiamnia do not appear in such quantities, on 

 exposed as well as on protected and suitable localities, a larger 

 variety of species is often found. The author remarks also a consi- 

 derable correspondence between the Lithothaninia of the Indian 

 Ocean and those of large areas of the Pacific within the tropics, 

 several of the species being identical as well as their mode of 

 occurrence. 



Thirteen species are recorded in the present paper as having 

 been collected by the "Sealark", two of which are new to science, 

 and were provisionally described in "Algologiske Notiser" III. 

 Critical notes are appended to each record. E. S. Gepp. 



Peragallo, H., Sur les Diatomees de l'Aquarium ä 0. [Oscil- 

 latoria] Cortiana du Laboratoire de Banvuls-sur-mer (C. R. 

 Soc. Bol. Paris. 7 Janv. 1908.) 



Les Diatomees proviennent du dragage initial et n'ont pas ete 

 amenees par l'eau des conduites; elles se sont propagees depuis 

 plus de cinq annees dans l'aquarium et, selon toutes vraisemblances, 

 les Oscillariees rouges observees par M. Sauvageau vivaient aussi 

 ä la meme profondeur de 35 metres. Cet aquarium renferme 63 

 especes et 9 varietes de Diatomees. La plupart sont des formes de 

 fonds. M. Peragallo y a observe unc espece californienne interes- 

 sante, le Gephyria tnedia. Les sondages faits au Laboratoire Arago 

 ont d'ailleurs constamment rapporte des formes tropicales inconnues 

 jusqu'alors dans la Mediterranee. P. Hariot. 



Sauvagt'au, C, A propos d'Oscillariees rouges observees 

 dans un aquarium du laboratoire de Banvuls-sur-mer. 

 (C. R. Soc. Biol. Paris. 7 Janv. 1908.) 



Dans un bassin du Laboratoire de Banyuls, M. Sauvageau a 



